The present invention relates to adhesive tape and more particularly to a tab for marking the start of a roll of adhesive tape and for facilitating the initial removal of tape from the roll.
It is common for adhesive tape to be supplied in the form of individual rolls of material from which a user can remove desired tape lengths. These individual rolls of adhesive tape may be manufactured by any number of known methods. One typical method includes unwinding a large, wide supply roll of adhesive tape material, which is subsequently slit in the longitudinal direction and wound circumferentially into individual finished product rolls. More specifically, each length of tape, starting at a leading end, is typically wound on itself to adhere each wrap of tape to an adjacent, underlying wrap of tape until a desired length of tape is wound around the roll. The tape is then severed from the supply roll to define a trailing end of the tape and to complete the individual product roll.
In some cases, the end of the last wrap of tape is adhered directly to the underlying wrap, which may make it difficult for a user to locate and grasp the tape to begin unwinding the tape from the roll. To remove the tape from such a roll, the user must first locate the trailing end of the tape by closely inspecting the roll, which can be particularly difficult when the tape is transparent or when the tape is thin. The user will then often attempt to separate the tape from the underlying roll to which it is adhered by inserting a sharp object under the trailing end of the tape, such as scissors or a fingernail. Preferably, the user will be able to separate the tape from the underlying roll across the entire width of the tape. However, if the user cuts or damages the trailing end of the tape, a portion of the tape on one side of the cut may remain adhered to the roll while the user is pulling the portion on the other side of the cut away from the roll When this happens, the tape may split or tear diagonally across the width of the tape, thereby leaving a slivered or torn portion of the tape adhered to the roll. The user must then again attempt to grasp the slivered end portion of the tape to remove the tape from the roll, which can be time consuming and frustrating. In some cases, the user may also cause undesirable damage to several underlying tape layers when using a sharp object to separate the tape from the roll. When this happens, the user may encounter problems with the tape tearing or breaking as each subsequent wrap of tape is unwound from the roll.
In order to provide an easier way for users to find the trailing end of the tape roll to begin removing tape from the roll, it is known to cover or deaden a portion of the tape during the manufacturing process by placing a piece non-adhesive material often referred to as a xe2x80x9ctabxe2x80x9d on the adhesive side of the tape near the trailing end of the tape roll. To properly position a tab relative to the end of the tape, the tab is typically placed on the length of tape after it is unwound from a supply roll and before it is subsequently wound onto a finished product roll. The length of tape is then cut at a predetermined position relative to the tab. In some situations, it is desirable to cut the tape to provide an xe2x80x9covertabxe2x80x9d portion, where a portion of the tape adjacent to the trailing tape end extends beyond the tab, as shown in FIG. 1. As illustrated, a tab 10 is positioned at a distance X from the trailing end of the tape so that the end or overtabbed portion can adhere to the underlying roll, while the portion having the tab 10 is positioned adjacent to the roll without adhering to the roll. It is often preferable that the length of the overtabbed portion is long enough to keep the trailing end of the tape adhered to the roll to prevent the roll from becoming tangled with other tape rolls during processing, but short enough that the user only needs to remove a small portion of tape from the roll before the tab can be grasped.
It can be difficult, however, to accurately position the tab on each finished product roll during the manufacturing process. Inaccurate cutting of the tape and/or inaccurate placement of the tab relative to the trailing end of the tape roll can cause problems in the finished product rolls. For example, when the tape is cut so that the overtabbed portion is longer than desired, a large length of tape adjacent to the trailing tape end is exposed to and adheres to the underlying roll, thereby diminishing or eliminating the usefulness of a tab. For another example, the tape may be cut so that the overtabbed portion is shorter than desired. In this case, the small overtabbed portion may not provide enough exposed adhesive to keep the trailing end of the tape adhered to the roll. This is particularly true when the tab material is stiffer than the tape and therefore does not easily conform to the curve of the tape roll unless it is sufficiently adhered to the roll surface. In these cases, the trailing end of the tape is free from the roll, including the tab and a small area of exposed adhesive. This exposed adhesive can cause manufacturing and processing problems when the adhesive sticks to other tape rolls or manufacturing equipment.
Another problem may also be created in the manufacturing process when the tape is cut within the portion that contains the tab, thereby cutting the tab into two portions. The first portion of the tab will then extend from the tape roll to the trailing end of the tape and leave no overtabbed portion on the product roll to keep the end of the tape adhered to the roll. Thus, the trailing end of the tape is free from the roll. In addition, the second portion of the tab remains on the end of the supply roll, which is often subsequently used at the beginning of the next roll of finished product. This second tab portion may then become the start or leading end of the next product roll, which may cause an undesirable bulge in the tape roll in the area of the tab as subsequent wraps of tape are wound over this tab piece 10, as shown in FIG. 2.
In some situations, it may not be desirable to provide an overtabbed portion on a tape roll. Rather, it may be preferable for the trailing end of the tape to be free from the underlying roll so that the user can easily locate and grasp an adhesive free tape end to unwrap the tape from the roll. However, the same manufacturing issues encountered when trying to accurately place a tab relative to the end of an overtabbed roll are also a concern when trying to position a tab relative to the trailing tape end so that the end portion is free from the roll. In other words, it is also difficult to accurately position the tab on each finished product roll so that it extends only to the end of the tape roll without leaving an overtabbed portion of adhesive tape at the end of the supply roll.
In one aspect of this invention, a method of making a roll of adhesive tape is provided, wherein the method comprises the steps of providing a length of tape having a leading end, a trailing end, a first side, and a second side opposite the first side, wherein the second side of the tape is at least partially covered with pressure sensitive adhesive and providing a tab having first and second opposite ends, a length between the first and second ends, a first side, and a second side, wherein at least a portion of the second side of the tab is covered with pressure sensitive adhesive. The method further comprises advancing the length of tape along a tape path, positioning the leading tape end about a central tape roll axis, and circumferentially winding the length of tape about the axis until a next to last, or penultimate tape layer is wound, wherein the penultimate tape layer has a circumference. The adhesive-covered portion of the second side of the tab is applied to the first side of the tape so that the second end of the tab is spaced from the trailing end of the tape length by a predetermined distance, wherein the predetermined distance is at least as long as the circumference of the penultimate layer of the tape roll and no longer than a total distance of the circumference of the penultimate layer and the length of the tab. The final layer of the tape length is circumferentially wound around the penultimate tape layer so that the trailing end of the tape overlays the tab between the first and second ends of the tab.
Also provided is a tape roll comprising a central tape roll axis, a length of tape having a leading end, a trailing end opposite the leading end, a first side, and a second side opposite the first side, wherein the second side of the tape is at least partially covered with pressure sensitive adhesive, and wherein the tape is circumferentially wound about the axis until a plurality of adjacent tape layers are wound, and a tab having first and second opposite ends, a first side, and a second side opposite the first side, wherein at least a portion of the second side of the tab is covered with pressure sensitive adhesive. In accordance with the invention the adhesive portion of the second side of the tab is adhered to the first side of the tape on a penultimate tape layer of the roll so that the trailing end of the tape overlays the tab between the first and second ends of the tab.